https://www.carsguide.com.au/car-reviews/mazda-cx-5-53914#crosshead-driving
Australian car review of the new CX5 says:
Mazda's efforts to reduce the level of cabin noise have been extensive... and they've worked. New sound deadening in multiple points around the car – including underneath the rear end, the doors and the firewall (the wall between the engine and the cabin) –
along with a thicker windscreen and better seals and panel gaps is just part of the fix for what was a noticeable weakness in the first CX-5. More insulation in the body pillars and more 'out of sight' carpet also reduce road noise levels in the cabin. In fact, Mazda says the reductions are the equivalent of
dropping 20km/h in road speed.
So cruising at 75 MPH in a 2017 should be like cruising at 63 MPH in a 16.5